Table 1. Demographic Characteristics of Women by Prepregnancy Body Mass Index Category, British Columbia, Canada, 2008-2020.
| Characteristic | Women, No. (%) | |||||
|---|---|---|---|---|---|---|
| Underweight (n = 22 396) | Normal (n = 231 583) | Overweight (n = 83 887) | Obesity class | |||
| I (n = 33363) | II (n = 13 308) | III (n = 7609) | ||||
| Maternal age, y | ||||||
| Median (IQR) | 30.1 (26.3-33.7) | 31.6 (28.1-35.0) | 31.6 (28.0-35.1) | 31.3 (27.6-34.9) | 31.1 (27.4-34.7) | 31.4 (27.8-34.9) |
| <20 | 779 (3.5) | 4443 (1.9) | 1276 (1.5) | 455 (1.4) | 166 (1.3) | 76 (1.0) |
| 20-24 | 3239 (14.5) | 21 908 (9.5) | 8467 (10.1) | 3855 (11.6) | 1592 (12.0) | 806 (10.6) |
| 25-34 | 14 394 (64.3) | 146 819 (63.4) | 52 146 (62.2) | 20 744 (62.4) | 8381 (63.0) | 4827 (63.4) |
| 35-39 | 3314 (14.8) | 48 101 (20.8) | 17 769 (21.2) | 6726 (20.2) | 2590 (19.5) | 1553 (20.4) |
| ≥40 | 670 (2.99) | 10 312 (4.5) | 4229 (5.0) | 1483 (4.5) | 579 (4.4) | 347 (4.6) |
| Parity | ||||||
| Nulliparous | 12 554 (56.1) | 117 770 (50.9) | 37 211 (44.4) | 13 667 (41.1) | 5355 (40.2) | 3000 (39.4) |
| 1 | 7199 (32.1) | 81 015 (35.0) | 30 935 (36.9) | 12 218 (36.7) | 4902 (36.8) | 2738 (36.0) |
| ≥2 | 2642 (11.8) | 32 780 (14.2) | 15 728 (18.8) | 7375 (22.2) | 3050 (22.9) | 1869 (24.6) |
| Maternal height, cm | ||||||
| Median (IQR) | 165 (160-170) | 165 (160-170) | 164 (160-169) | 164 (160-169) | 165 (160-170) | 165 (160-170) |
| <165 | 10 631 (47.5) | 114 967 (49.6) | 42 239 (50.4) | 16 695 (50.2) | 6299 (47.3) | 3705 (48.7) |
| 165-168 | 5852 (26.1) | 55 105 (23.8) | 19 807 (23.6) | 7900 (23.8) | 3366 (25.3) | 1889 (24.8) |
| 169-172 | 2507 (11.2) | 27 675 (12.0) | 10 043 (12.0) | 3893 (11.7) | 1669 (12.5) | 928 (12.2) |
| ≥173 | 3406 (15.2) | 33 836 (14.6) | 11 798 (14.1) | 4775 (14.4) | 1974 (14.8) | 1087 (14.3) |
| Smoking | ||||||
| Yes | 1727 (7.7) | 12 954 (5.6) | 6159 (7.3) | 3241 (9.7) | 1462 (11.0) | 881 (11.6) |
| No | 20 669 (92.3) | 218 629 (94.4) | 77 728 (92.7) | 30 022 (90.3) | 11 846 (89.0) | 6728 (88.4) |